Electric welding equipment is utilized in a variety of applications. Generally, a welding power supply creates an electric arc between an electrode and a workpiece. The heat generated by the electric arc melts a filler material, which may comprise a consumable electrode, and transfers the filler material to the workpiece. A shielding gas, vapor, and/or slag may be utilized to protect the weld area from atmospheric gases.
Electric welding equipment generally includes a grounding device that connects to the workpiece. If properly connected, the grounding device grounds the workpiece and provides a stable welding environment. However, in some instances, the grounding device is not properly connected to the workpiece. In these instances, the welding power supply may self-adjust the voltage and/or current to maintain the electric arc between the electrode and the workpiece. The voltage and/or current adjustment may result in the weld parameters, for example the voltage, current, and/or weld speed, being outside of a predefined weld parameter range set by the welder before commencing the welding operation, resulting in an unacceptable weld. In extreme circumstances, an improper ground connection between a grounding device and a workpiece may result in an inadvertent arc between the electrode or grounding device and a nearby structure that is not the target of the welding operation and may cause unintended damage to the structure.
To address the aforementioned problems, typical welding ground detection systems and methods detect a voltage, a current, a resistance, and/or an impedance of a ground connection. Upon detection of an improper voltage, current, resistance, and/or impedance, these systems and methods prevent current flow through the welding equipment and thereby shut down the welding operation. For example, U.S. Pat. No. 6,657,163, which is incorporated by reference herein in its entirety, discloses a system for selectively allowing current flow through welding equipment based upon the detected impedance between a grounding device and a welding power supply. Thus, typical welding equipment is operable until an improper voltage, current, resistance, and/or impedance is detected. However, during this time period, which may include a delay between detection and disablement of the equipment, an inadvertent arc may occur. In addition, in some circumstances, welding equipment may be operable even though a grounding device is not connected to a workpiece. For example, a welder may forget to connect a grounding device to a workpiece, resulting in an improperly grounded workpiece. However, if the grounding device is contacting a conductive surface, or if a facility ground is present, the welding detection system and method commonly detects a ground and allows current flow. In many of these circumstances, the welder does not realize the improperly connected grounding device and begins welding, which may result in an unacceptable weld and/or an inadvertent arc between the electrode or grounding device and a nearby structure.
None of the welding ground detection systems or methods currently in existence or otherwise known to those of skill in the art address the aforementioned problems.